Access cover assembly

Abstract

An access cover assembly (10) has a cover member (12) and a frame member (14). The cover member has twelve vertical wall sections (36) with adjoining vertical edges (38) and twelve canted surfaces (40) with adjoining angled edges (46) depending downwardly from said vertical wall sections (36). The frame member has an upwardly facing frusto-conical section (80) and a number of substantially vertical edges (82) depending downwardly from an inner periphery (81) of said section (80), said inner periphery (81) being shaped such that when said angled edges (46) engage said inner periphery (81) when the cover is partially seated in the frame, the cover rotates towards a fully seated position in the frame member (14), whereupon the cover falls into and is locked within the frame member.

The embodiments in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. An access cover assembly having a cover member and an annular frame member, said assembly characterized by; said cover member having a substantially circular outer peripheral edge with a central axis extending transverse to the plane containing the peripheral edge;   said cover member having a plurality of downwardly facing flat surfaces circumferentially spaced about a center vertical axis of said cover with said flat surfaces being canted such that a respective inner peripheral edge of a respective surface is positioned below a respective outer peripheral edge of said respective surface, each of said canted flat surfaces adjoining another canted flat surface at an angled edge;   a respective substantially vertical and flat wall section extending upwardly from a respective outer peripheral edge of each canted flat surface;   said frame member having a center aperture and an upwardly facing frusto-conical surface about said center aperture which extends outwardly and upwardly;   said frame member having a plurality of substantially vertical and flat wall sections extending downwardly from an inner periphery of said upwardly facing frusto-conical section and positioned to allow said vertical and flat wall sections of said cover member to be locked within said center aperture at predetermined rotated positions about said central axis; and   said inner periphery of said upwardly facing frusto-conical section being shaped such that upon engagement of the angled edges of the cover member with said inner periphery, such as occurs when the cover member is placed in the frame member in a position other than one of said predetermined positions, the cover rotates towards one of said predetermined positions wherein said cover member drops into and is fully seated in said frame member and locked against further relative rotation with respect to said frame member.   
     
     
       2. An access cover assembly having a cover member and an annular frame member, said assembly characterized by; said cover member having a substantially circular outer peripheral rim section with a central axis extending transverse to the plane containing the peripheral rim section;   a first series of downwardly depending edges being circumferentially spaced about said central vertical axis and radially inward from an outer periphery of said rim section;   a second series of downwardly depending edges circumferentially spaced about said central vertical axis and canted radially inwardly and downwardly from a lower edge of said respective first series of downwardly depending edges;   said frame member having a center aperture and an upwardly facing surface about said center aperture;   said frame member having wall sections extending downwardly from an inner periphery of said upwardly facing surface and positioned to allow said first and second series of downwardly depending edges to be received within said center aperture at predetermined rotated positions about said central axis; and   said inner periphery of said upwardly facing surface being shaped such that upon engagement of said second series of edges of the cover member with said inner periphery of the frame member, such as occurs when the cover member is placed in the frame member in a position other than one of said predetermined positions, the cover rotates towards one of said predetermined rotated positions wherein said cover member drops into and is seated in said frame member and locked against further relative rotation with respect to said frame member.   
     
     
       3. An access cover assembly as defined in claim 2 further characterized by: said first series of downwardly depending edges being side edges of substantially vertical wall sections of said cover member positioned radially within and below said outer periphery of said rim section.   
     
     
       4. An access cover assembly as defined in claim 3 further characterized by: said substantially vertical wall sections of said cover member being substantially flat.   
     
     
       5. An access cover assembly as defined in claim 3 further characterized by: said second series of downwardly depending edges being side edges of surfaces which are canted radially inwardly and downwardly from a lower edge of said respective vertical wall sections.   
     
     
       6. An access cover assembly as defined in claim 5 further characterized by: said canted surfaces or said cover member being substantially flat.   
     
     
       7. A cover member for an access cover assembly, said cover member characterized by: a substantially circular outer peripheral edge with a central axis extending transverse to the plane containing the peripheral edge;   a plurality of downwardly facing flat surfaces circumferentially spaced about a center vertical axis of said cover with said flat surfaces being canted such that a respective inner peripheral edge of a respective surface is positioned below a respective outer peripheral edge of said respective surface;   a respective substantially vertical and flat wall section extending upwardly from a respective outer peripheral edge of each canted flat surface;   a downwardly facing frusto-conical section extending radially outwardly and upwardly from a top edge of said vertical wall sections; and   said outer peripheral rim section including a downwardly and radially outwardly extending lip.   
     
     
       8. A frame member for an access cover assembly, said frame member characterized by: a center aperture and an upwardly facing frusto-conical surface about said center aperture and extending outwardly and upwardly;   a plurality of wall sections extending downwardly from an inner periphery of said upwardly facing frusto-conical section and positioned to allow said vertical wall sections of said cover member to be received within said center aperture at predetermined rotated positions about said central axis; and   said inner periphery of said upwardly facing frusto-conical surface being shaped such that upon engagement of said angled edges of said cover member with said inner periphery, such as occurs when the cover member is placed in the frame member in a position other than one of said predetermined positions, the cover rotates towards one of said predetermined rotated positions wherein said cover member drops into and is seated in said frame member and locked against relative rotation with respect to said frame member.   
     
     
       9. A frame member for an access cover assembly as defined in claim 8 further characterized by: a recessed annular seating area situated about said frusto-conical section; and   a radially outer and raised ridge section having a plurality of notches therein for providing access of a lifting tool to a lip section of a cover member positioned in said recessed annular seating area.   
     
     
       10. An access cover assembly having a cover member and an annular frame member, said assembly characterized by: said cover member having a substantially circular outer peripheral edge with a central axis extending transverse to the plane containing the peripheral edge;   said frame member having a center aperture and an upwardly facing annular surface about said center aperture and extending outwardly and upwardly;   vertical locking means for seating said cover and locking said cover in a plurality of predetermined rotated positions;   guidance means for causing said cover member to selectively rotate in both clockwise and counter-clockwise towards one of said predetermined rotated positions;   said cover member having first means downwardly depending from and radially positioned inwardly from said outer peripheral edge section for engagement, when in one of said predetermined rotated positions, with said vertically extending means of said frame member; and   second means depending downwardly from and radially positioned inwardly from said first means for sliding engagement with said guidance means of the frame member whereby the cover member rotates selectively clockwise and counter-clockwise towards one of said predetermined rotated positions wherein said cover member, when in one of said predetermined rotated positions, ceases to rotate and drops vertically into and is seated in said frame member and locked against relative rotation with respect to said frame member.   
     
     
       11. An access cover assembly having a cover member and an annular frame member, said assembly characterized by: said cover member having a substantially circular outer peripheral edge with a central axis extending transverse to the place containing the peripheral edge;   said frame member having a center aperture, an upwardly facing annular surface about said center aperture, and engagement means for seating said cover and locking said cover in a plurality of predetermined rotated positions;   said cover and frame ember having complementary guidance means for rotating said cover with respect to said frame member such that when said cover is partially seated in said frame member said cover rotates selectively clockwise and counter-clockwise towards one of said plurality of predetermined rotated positions and, when in one of said plurality of predetermined rotated positions, said cover member ceases to rotate and drops vertically into and is fully seated in said frame member and locked against further relative rotation with respect to said frame member.